xref: /openbmc/linux/arch/x86/hyperv/ivm.c (revision c900529f3d9161bfde5cca0754f83b4d3c3e0220)
1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * Hyper-V Isolation VM interface with paravisor and hypervisor
4   *
5   * Author:
6   *  Tianyu Lan <Tianyu.Lan@microsoft.com>
7   */
8  
9  #include <linux/bitfield.h>
10  #include <linux/hyperv.h>
11  #include <linux/types.h>
12  #include <linux/slab.h>
13  #include <asm/svm.h>
14  #include <asm/sev.h>
15  #include <asm/io.h>
16  #include <asm/coco.h>
17  #include <asm/mem_encrypt.h>
18  #include <asm/mshyperv.h>
19  #include <asm/hypervisor.h>
20  #include <asm/mtrr.h>
21  #include <asm/io_apic.h>
22  #include <asm/realmode.h>
23  #include <asm/e820/api.h>
24  #include <asm/desc.h>
25  #include <uapi/asm/vmx.h>
26  
27  #ifdef CONFIG_AMD_MEM_ENCRYPT
28  
29  #define GHCB_USAGE_HYPERV_CALL	1
30  
31  union hv_ghcb {
32  	struct ghcb ghcb;
33  	struct {
34  		u64 hypercalldata[509];
35  		u64 outputgpa;
36  		union {
37  			union {
38  				struct {
39  					u32 callcode        : 16;
40  					u32 isfast          : 1;
41  					u32 reserved1       : 14;
42  					u32 isnested        : 1;
43  					u32 countofelements : 12;
44  					u32 reserved2       : 4;
45  					u32 repstartindex   : 12;
46  					u32 reserved3       : 4;
47  				};
48  				u64 asuint64;
49  			} hypercallinput;
50  			union {
51  				struct {
52  					u16 callstatus;
53  					u16 reserved1;
54  					u32 elementsprocessed : 12;
55  					u32 reserved2         : 20;
56  				};
57  				u64 asunit64;
58  			} hypercalloutput;
59  		};
60  		u64 reserved2;
61  	} hypercall;
62  } __packed __aligned(HV_HYP_PAGE_SIZE);
63  
64  /* Only used in an SNP VM with the paravisor */
65  static u16 hv_ghcb_version __ro_after_init;
66  
67  /* Functions only used in an SNP VM with the paravisor go here. */
hv_ghcb_hypercall(u64 control,void * input,void * output,u32 input_size)68  u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size)
69  {
70  	union hv_ghcb *hv_ghcb;
71  	void **ghcb_base;
72  	unsigned long flags;
73  	u64 status;
74  
75  	if (!hv_ghcb_pg)
76  		return -EFAULT;
77  
78  	WARN_ON(in_nmi());
79  
80  	local_irq_save(flags);
81  	ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
82  	hv_ghcb = (union hv_ghcb *)*ghcb_base;
83  	if (!hv_ghcb) {
84  		local_irq_restore(flags);
85  		return -EFAULT;
86  	}
87  
88  	hv_ghcb->ghcb.protocol_version = GHCB_PROTOCOL_MAX;
89  	hv_ghcb->ghcb.ghcb_usage = GHCB_USAGE_HYPERV_CALL;
90  
91  	hv_ghcb->hypercall.outputgpa = (u64)output;
92  	hv_ghcb->hypercall.hypercallinput.asuint64 = 0;
93  	hv_ghcb->hypercall.hypercallinput.callcode = control;
94  
95  	if (input_size)
96  		memcpy(hv_ghcb->hypercall.hypercalldata, input, input_size);
97  
98  	VMGEXIT();
99  
100  	hv_ghcb->ghcb.ghcb_usage = 0xffffffff;
101  	memset(hv_ghcb->ghcb.save.valid_bitmap, 0,
102  	       sizeof(hv_ghcb->ghcb.save.valid_bitmap));
103  
104  	status = hv_ghcb->hypercall.hypercalloutput.callstatus;
105  
106  	local_irq_restore(flags);
107  
108  	return status;
109  }
110  
rd_ghcb_msr(void)111  static inline u64 rd_ghcb_msr(void)
112  {
113  	return __rdmsr(MSR_AMD64_SEV_ES_GHCB);
114  }
115  
wr_ghcb_msr(u64 val)116  static inline void wr_ghcb_msr(u64 val)
117  {
118  	native_wrmsrl(MSR_AMD64_SEV_ES_GHCB, val);
119  }
120  
hv_ghcb_hv_call(struct ghcb * ghcb,u64 exit_code,u64 exit_info_1,u64 exit_info_2)121  static enum es_result hv_ghcb_hv_call(struct ghcb *ghcb, u64 exit_code,
122  				   u64 exit_info_1, u64 exit_info_2)
123  {
124  	/* Fill in protocol and format specifiers */
125  	ghcb->protocol_version = hv_ghcb_version;
126  	ghcb->ghcb_usage       = GHCB_DEFAULT_USAGE;
127  
128  	ghcb_set_sw_exit_code(ghcb, exit_code);
129  	ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
130  	ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
131  
132  	VMGEXIT();
133  
134  	if (ghcb->save.sw_exit_info_1 & GENMASK_ULL(31, 0))
135  		return ES_VMM_ERROR;
136  	else
137  		return ES_OK;
138  }
139  
hv_ghcb_terminate(unsigned int set,unsigned int reason)140  void __noreturn hv_ghcb_terminate(unsigned int set, unsigned int reason)
141  {
142  	u64 val = GHCB_MSR_TERM_REQ;
143  
144  	/* Tell the hypervisor what went wrong. */
145  	val |= GHCB_SEV_TERM_REASON(set, reason);
146  
147  	/* Request Guest Termination from Hypvervisor */
148  	wr_ghcb_msr(val);
149  	VMGEXIT();
150  
151  	while (true)
152  		asm volatile("hlt\n" : : : "memory");
153  }
154  
hv_ghcb_negotiate_protocol(void)155  bool hv_ghcb_negotiate_protocol(void)
156  {
157  	u64 ghcb_gpa;
158  	u64 val;
159  
160  	/* Save ghcb page gpa. */
161  	ghcb_gpa = rd_ghcb_msr();
162  
163  	/* Do the GHCB protocol version negotiation */
164  	wr_ghcb_msr(GHCB_MSR_SEV_INFO_REQ);
165  	VMGEXIT();
166  	val = rd_ghcb_msr();
167  
168  	if (GHCB_MSR_INFO(val) != GHCB_MSR_SEV_INFO_RESP)
169  		return false;
170  
171  	if (GHCB_MSR_PROTO_MAX(val) < GHCB_PROTOCOL_MIN ||
172  	    GHCB_MSR_PROTO_MIN(val) > GHCB_PROTOCOL_MAX)
173  		return false;
174  
175  	hv_ghcb_version = min_t(size_t, GHCB_MSR_PROTO_MAX(val),
176  			     GHCB_PROTOCOL_MAX);
177  
178  	/* Write ghcb page back after negotiating protocol. */
179  	wr_ghcb_msr(ghcb_gpa);
180  	VMGEXIT();
181  
182  	return true;
183  }
184  
hv_ghcb_msr_write(u64 msr,u64 value)185  static void hv_ghcb_msr_write(u64 msr, u64 value)
186  {
187  	union hv_ghcb *hv_ghcb;
188  	void **ghcb_base;
189  	unsigned long flags;
190  
191  	if (!hv_ghcb_pg)
192  		return;
193  
194  	WARN_ON(in_nmi());
195  
196  	local_irq_save(flags);
197  	ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
198  	hv_ghcb = (union hv_ghcb *)*ghcb_base;
199  	if (!hv_ghcb) {
200  		local_irq_restore(flags);
201  		return;
202  	}
203  
204  	ghcb_set_rcx(&hv_ghcb->ghcb, msr);
205  	ghcb_set_rax(&hv_ghcb->ghcb, lower_32_bits(value));
206  	ghcb_set_rdx(&hv_ghcb->ghcb, upper_32_bits(value));
207  
208  	if (hv_ghcb_hv_call(&hv_ghcb->ghcb, SVM_EXIT_MSR, 1, 0))
209  		pr_warn("Fail to write msr via ghcb %llx.\n", msr);
210  
211  	local_irq_restore(flags);
212  }
213  
hv_ghcb_msr_read(u64 msr,u64 * value)214  static void hv_ghcb_msr_read(u64 msr, u64 *value)
215  {
216  	union hv_ghcb *hv_ghcb;
217  	void **ghcb_base;
218  	unsigned long flags;
219  
220  	/* Check size of union hv_ghcb here. */
221  	BUILD_BUG_ON(sizeof(union hv_ghcb) != HV_HYP_PAGE_SIZE);
222  
223  	if (!hv_ghcb_pg)
224  		return;
225  
226  	WARN_ON(in_nmi());
227  
228  	local_irq_save(flags);
229  	ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
230  	hv_ghcb = (union hv_ghcb *)*ghcb_base;
231  	if (!hv_ghcb) {
232  		local_irq_restore(flags);
233  		return;
234  	}
235  
236  	ghcb_set_rcx(&hv_ghcb->ghcb, msr);
237  	if (hv_ghcb_hv_call(&hv_ghcb->ghcb, SVM_EXIT_MSR, 0, 0))
238  		pr_warn("Fail to read msr via ghcb %llx.\n", msr);
239  	else
240  		*value = (u64)lower_32_bits(hv_ghcb->ghcb.save.rax)
241  			| ((u64)lower_32_bits(hv_ghcb->ghcb.save.rdx) << 32);
242  	local_irq_restore(flags);
243  }
244  
245  /* Only used in a fully enlightened SNP VM, i.e. without the paravisor */
246  static u8 ap_start_input_arg[PAGE_SIZE] __bss_decrypted __aligned(PAGE_SIZE);
247  static u8 ap_start_stack[PAGE_SIZE] __aligned(PAGE_SIZE);
248  static DEFINE_PER_CPU(struct sev_es_save_area *, hv_sev_vmsa);
249  
250  /* Functions only used in an SNP VM without the paravisor go here. */
251  
252  #define hv_populate_vmcb_seg(seg, gdtr_base)			\
253  do {								\
254  	if (seg.selector) {					\
255  		seg.base = 0;					\
256  		seg.limit = HV_AP_SEGMENT_LIMIT;		\
257  		seg.attrib = *(u16 *)(gdtr_base + seg.selector + 5);	\
258  		seg.attrib = (seg.attrib & 0xFF) | ((seg.attrib >> 4) & 0xF00); \
259  	}							\
260  } while (0)							\
261  
snp_set_vmsa(void * va,bool vmsa)262  static int snp_set_vmsa(void *va, bool vmsa)
263  {
264  	u64 attrs;
265  
266  	/*
267  	 * Running at VMPL0 allows the kernel to change the VMSA bit for a page
268  	 * using the RMPADJUST instruction. However, for the instruction to
269  	 * succeed it must target the permissions of a lesser privileged
270  	 * (higher numbered) VMPL level, so use VMPL1 (refer to the RMPADJUST
271  	 * instruction in the AMD64 APM Volume 3).
272  	 */
273  	attrs = 1;
274  	if (vmsa)
275  		attrs |= RMPADJUST_VMSA_PAGE_BIT;
276  
277  	return rmpadjust((unsigned long)va, RMP_PG_SIZE_4K, attrs);
278  }
279  
snp_cleanup_vmsa(struct sev_es_save_area * vmsa)280  static void snp_cleanup_vmsa(struct sev_es_save_area *vmsa)
281  {
282  	int err;
283  
284  	err = snp_set_vmsa(vmsa, false);
285  	if (err)
286  		pr_err("clear VMSA page failed (%u), leaking page\n", err);
287  	else
288  		free_page((unsigned long)vmsa);
289  }
290  
hv_snp_boot_ap(int cpu,unsigned long start_ip)291  int hv_snp_boot_ap(int cpu, unsigned long start_ip)
292  {
293  	struct sev_es_save_area *vmsa = (struct sev_es_save_area *)
294  		__get_free_page(GFP_KERNEL | __GFP_ZERO);
295  	struct sev_es_save_area *cur_vmsa;
296  	struct desc_ptr gdtr;
297  	u64 ret, retry = 5;
298  	struct hv_enable_vp_vtl *start_vp_input;
299  	unsigned long flags;
300  
301  	if (!vmsa)
302  		return -ENOMEM;
303  
304  	native_store_gdt(&gdtr);
305  
306  	vmsa->gdtr.base = gdtr.address;
307  	vmsa->gdtr.limit = gdtr.size;
308  
309  	asm volatile("movl %%es, %%eax;" : "=a" (vmsa->es.selector));
310  	hv_populate_vmcb_seg(vmsa->es, vmsa->gdtr.base);
311  
312  	asm volatile("movl %%cs, %%eax;" : "=a" (vmsa->cs.selector));
313  	hv_populate_vmcb_seg(vmsa->cs, vmsa->gdtr.base);
314  
315  	asm volatile("movl %%ss, %%eax;" : "=a" (vmsa->ss.selector));
316  	hv_populate_vmcb_seg(vmsa->ss, vmsa->gdtr.base);
317  
318  	asm volatile("movl %%ds, %%eax;" : "=a" (vmsa->ds.selector));
319  	hv_populate_vmcb_seg(vmsa->ds, vmsa->gdtr.base);
320  
321  	vmsa->efer = native_read_msr(MSR_EFER);
322  
323  	asm volatile("movq %%cr4, %%rax;" : "=a" (vmsa->cr4));
324  	asm volatile("movq %%cr3, %%rax;" : "=a" (vmsa->cr3));
325  	asm volatile("movq %%cr0, %%rax;" : "=a" (vmsa->cr0));
326  
327  	vmsa->xcr0 = 1;
328  	vmsa->g_pat = HV_AP_INIT_GPAT_DEFAULT;
329  	vmsa->rip = (u64)secondary_startup_64_no_verify;
330  	vmsa->rsp = (u64)&ap_start_stack[PAGE_SIZE];
331  
332  	/*
333  	 * Set the SNP-specific fields for this VMSA:
334  	 *   VMPL level
335  	 *   SEV_FEATURES (matches the SEV STATUS MSR right shifted 2 bits)
336  	 */
337  	vmsa->vmpl = 0;
338  	vmsa->sev_features = sev_status >> 2;
339  
340  	ret = snp_set_vmsa(vmsa, true);
341  	if (!ret) {
342  		pr_err("RMPADJUST(%llx) failed: %llx\n", (u64)vmsa, ret);
343  		free_page((u64)vmsa);
344  		return ret;
345  	}
346  
347  	local_irq_save(flags);
348  	start_vp_input = (struct hv_enable_vp_vtl *)ap_start_input_arg;
349  	memset(start_vp_input, 0, sizeof(*start_vp_input));
350  	start_vp_input->partition_id = -1;
351  	start_vp_input->vp_index = cpu;
352  	start_vp_input->target_vtl.target_vtl = ms_hyperv.vtl;
353  	*(u64 *)&start_vp_input->vp_context = __pa(vmsa) | 1;
354  
355  	do {
356  		ret = hv_do_hypercall(HVCALL_START_VP,
357  				      start_vp_input, NULL);
358  	} while (hv_result(ret) == HV_STATUS_TIME_OUT && retry--);
359  
360  	local_irq_restore(flags);
361  
362  	if (!hv_result_success(ret)) {
363  		pr_err("HvCallStartVirtualProcessor failed: %llx\n", ret);
364  		snp_cleanup_vmsa(vmsa);
365  		vmsa = NULL;
366  	}
367  
368  	cur_vmsa = per_cpu(hv_sev_vmsa, cpu);
369  	/* Free up any previous VMSA page */
370  	if (cur_vmsa)
371  		snp_cleanup_vmsa(cur_vmsa);
372  
373  	/* Record the current VMSA page */
374  	per_cpu(hv_sev_vmsa, cpu) = vmsa;
375  
376  	return ret;
377  }
378  
379  #else
hv_ghcb_msr_write(u64 msr,u64 value)380  static inline void hv_ghcb_msr_write(u64 msr, u64 value) {}
hv_ghcb_msr_read(u64 msr,u64 * value)381  static inline void hv_ghcb_msr_read(u64 msr, u64 *value) {}
382  #endif /* CONFIG_AMD_MEM_ENCRYPT */
383  
384  #ifdef CONFIG_INTEL_TDX_GUEST
hv_tdx_msr_write(u64 msr,u64 val)385  static void hv_tdx_msr_write(u64 msr, u64 val)
386  {
387  	struct tdx_hypercall_args args = {
388  		.r10 = TDX_HYPERCALL_STANDARD,
389  		.r11 = EXIT_REASON_MSR_WRITE,
390  		.r12 = msr,
391  		.r13 = val,
392  	};
393  
394  	u64 ret = __tdx_hypercall(&args);
395  
396  	WARN_ONCE(ret, "Failed to emulate MSR write: %lld\n", ret);
397  }
398  
hv_tdx_msr_read(u64 msr,u64 * val)399  static void hv_tdx_msr_read(u64 msr, u64 *val)
400  {
401  	struct tdx_hypercall_args args = {
402  		.r10 = TDX_HYPERCALL_STANDARD,
403  		.r11 = EXIT_REASON_MSR_READ,
404  		.r12 = msr,
405  	};
406  
407  	u64 ret = __tdx_hypercall_ret(&args);
408  
409  	if (WARN_ONCE(ret, "Failed to emulate MSR read: %lld\n", ret))
410  		*val = 0;
411  	else
412  		*val = args.r11;
413  }
414  
hv_tdx_hypercall(u64 control,u64 param1,u64 param2)415  u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2)
416  {
417  	struct tdx_hypercall_args args = { };
418  
419  	args.r10 = control;
420  	args.rdx = param1;
421  	args.r8  = param2;
422  
423  	(void)__tdx_hypercall_ret(&args);
424  
425  	return args.r11;
426  }
427  
428  #else
hv_tdx_msr_write(u64 msr,u64 value)429  static inline void hv_tdx_msr_write(u64 msr, u64 value) {}
hv_tdx_msr_read(u64 msr,u64 * value)430  static inline void hv_tdx_msr_read(u64 msr, u64 *value) {}
431  #endif /* CONFIG_INTEL_TDX_GUEST */
432  
433  #if defined(CONFIG_AMD_MEM_ENCRYPT) || defined(CONFIG_INTEL_TDX_GUEST)
hv_ivm_msr_write(u64 msr,u64 value)434  void hv_ivm_msr_write(u64 msr, u64 value)
435  {
436  	if (!ms_hyperv.paravisor_present)
437  		return;
438  
439  	if (hv_isolation_type_tdx())
440  		hv_tdx_msr_write(msr, value);
441  	else if (hv_isolation_type_snp())
442  		hv_ghcb_msr_write(msr, value);
443  }
444  
hv_ivm_msr_read(u64 msr,u64 * value)445  void hv_ivm_msr_read(u64 msr, u64 *value)
446  {
447  	if (!ms_hyperv.paravisor_present)
448  		return;
449  
450  	if (hv_isolation_type_tdx())
451  		hv_tdx_msr_read(msr, value);
452  	else if (hv_isolation_type_snp())
453  		hv_ghcb_msr_read(msr, value);
454  }
455  
456  /*
457   * hv_mark_gpa_visibility - Set pages visible to host via hvcall.
458   *
459   * In Isolation VM, all guest memory is encrypted from host and guest
460   * needs to set memory visible to host via hvcall before sharing memory
461   * with host.
462   */
hv_mark_gpa_visibility(u16 count,const u64 pfn[],enum hv_mem_host_visibility visibility)463  static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
464  			   enum hv_mem_host_visibility visibility)
465  {
466  	struct hv_gpa_range_for_visibility *input;
467  	u16 pages_processed;
468  	u64 hv_status;
469  	unsigned long flags;
470  
471  	/* no-op if partition isolation is not enabled */
472  	if (!hv_is_isolation_supported())
473  		return 0;
474  
475  	if (count > HV_MAX_MODIFY_GPA_REP_COUNT) {
476  		pr_err("Hyper-V: GPA count:%d exceeds supported:%lu\n", count,
477  			HV_MAX_MODIFY_GPA_REP_COUNT);
478  		return -EINVAL;
479  	}
480  
481  	local_irq_save(flags);
482  	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
483  
484  	if (unlikely(!input)) {
485  		local_irq_restore(flags);
486  		return -EINVAL;
487  	}
488  
489  	input->partition_id = HV_PARTITION_ID_SELF;
490  	input->host_visibility = visibility;
491  	input->reserved0 = 0;
492  	input->reserved1 = 0;
493  	memcpy((void *)input->gpa_page_list, pfn, count * sizeof(*pfn));
494  	hv_status = hv_do_rep_hypercall(
495  			HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY, count,
496  			0, input, &pages_processed);
497  	local_irq_restore(flags);
498  
499  	if (hv_result_success(hv_status))
500  		return 0;
501  	else
502  		return -EFAULT;
503  }
504  
505  /*
506   * hv_vtom_set_host_visibility - Set specified memory visible to host.
507   *
508   * In Isolation VM, all guest memory is encrypted from host and guest
509   * needs to set memory visible to host via hvcall before sharing memory
510   * with host. This function works as wrap of hv_mark_gpa_visibility()
511   * with memory base and size.
512   */
hv_vtom_set_host_visibility(unsigned long kbuffer,int pagecount,bool enc)513  static bool hv_vtom_set_host_visibility(unsigned long kbuffer, int pagecount, bool enc)
514  {
515  	enum hv_mem_host_visibility visibility = enc ?
516  			VMBUS_PAGE_NOT_VISIBLE : VMBUS_PAGE_VISIBLE_READ_WRITE;
517  	u64 *pfn_array;
518  	int ret = 0;
519  	bool result = true;
520  	int i, pfn;
521  
522  	pfn_array = kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
523  	if (!pfn_array)
524  		return false;
525  
526  	for (i = 0, pfn = 0; i < pagecount; i++) {
527  		pfn_array[pfn] = virt_to_hvpfn((void *)kbuffer + i * HV_HYP_PAGE_SIZE);
528  		pfn++;
529  
530  		if (pfn == HV_MAX_MODIFY_GPA_REP_COUNT || i == pagecount - 1) {
531  			ret = hv_mark_gpa_visibility(pfn, pfn_array,
532  						     visibility);
533  			if (ret) {
534  				result = false;
535  				goto err_free_pfn_array;
536  			}
537  			pfn = 0;
538  		}
539  	}
540  
541   err_free_pfn_array:
542  	kfree(pfn_array);
543  	return result;
544  }
545  
hv_vtom_tlb_flush_required(bool private)546  static bool hv_vtom_tlb_flush_required(bool private)
547  {
548  	return true;
549  }
550  
hv_vtom_cache_flush_required(void)551  static bool hv_vtom_cache_flush_required(void)
552  {
553  	return false;
554  }
555  
hv_is_private_mmio(u64 addr)556  static bool hv_is_private_mmio(u64 addr)
557  {
558  	/*
559  	 * Hyper-V always provides a single IO-APIC in a guest VM.
560  	 * When a paravisor is used, it is emulated by the paravisor
561  	 * in the guest context and must be mapped private.
562  	 */
563  	if (addr >= HV_IOAPIC_BASE_ADDRESS &&
564  	    addr < (HV_IOAPIC_BASE_ADDRESS + PAGE_SIZE))
565  		return true;
566  
567  	/* Same with a vTPM */
568  	if (addr >= VTPM_BASE_ADDRESS &&
569  	    addr < (VTPM_BASE_ADDRESS + PAGE_SIZE))
570  		return true;
571  
572  	return false;
573  }
574  
hv_vtom_init(void)575  void __init hv_vtom_init(void)
576  {
577  	enum hv_isolation_type type = hv_get_isolation_type();
578  
579  	switch (type) {
580  	case HV_ISOLATION_TYPE_VBS:
581  		fallthrough;
582  	/*
583  	 * By design, a VM using vTOM doesn't see the SEV setting,
584  	 * so SEV initialization is bypassed and sev_status isn't set.
585  	 * Set it here to indicate a vTOM VM.
586  	 *
587  	 * Note: if CONFIG_AMD_MEM_ENCRYPT is not set, sev_status is
588  	 * defined as 0ULL, to which we can't assigned a value.
589  	 */
590  #ifdef CONFIG_AMD_MEM_ENCRYPT
591  	case HV_ISOLATION_TYPE_SNP:
592  		sev_status = MSR_AMD64_SNP_VTOM;
593  		cc_vendor = CC_VENDOR_AMD;
594  		break;
595  #endif
596  
597  	case HV_ISOLATION_TYPE_TDX:
598  		cc_vendor = CC_VENDOR_INTEL;
599  		break;
600  
601  	default:
602  		panic("hv_vtom_init: unsupported isolation type %d\n", type);
603  	}
604  
605  	cc_set_mask(ms_hyperv.shared_gpa_boundary);
606  	physical_mask &= ms_hyperv.shared_gpa_boundary - 1;
607  
608  	x86_platform.hyper.is_private_mmio = hv_is_private_mmio;
609  	x86_platform.guest.enc_cache_flush_required = hv_vtom_cache_flush_required;
610  	x86_platform.guest.enc_tlb_flush_required = hv_vtom_tlb_flush_required;
611  	x86_platform.guest.enc_status_change_finish = hv_vtom_set_host_visibility;
612  
613  	/* Set WB as the default cache mode. */
614  	mtrr_overwrite_state(NULL, 0, MTRR_TYPE_WRBACK);
615  }
616  
617  #endif /* defined(CONFIG_AMD_MEM_ENCRYPT) || defined(CONFIG_INTEL_TDX_GUEST) */
618  
hv_get_isolation_type(void)619  enum hv_isolation_type hv_get_isolation_type(void)
620  {
621  	if (!(ms_hyperv.priv_high & HV_ISOLATION))
622  		return HV_ISOLATION_TYPE_NONE;
623  	return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
624  }
625  EXPORT_SYMBOL_GPL(hv_get_isolation_type);
626  
627  /*
628   * hv_is_isolation_supported - Check system runs in the Hyper-V
629   * isolation VM.
630   */
hv_is_isolation_supported(void)631  bool hv_is_isolation_supported(void)
632  {
633  	if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
634  		return false;
635  
636  	if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
637  		return false;
638  
639  	return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
640  }
641  
642  DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
643  
644  /*
645   * hv_isolation_type_snp - Check if the system runs in an AMD SEV-SNP based
646   * isolation VM.
647   */
hv_isolation_type_snp(void)648  bool hv_isolation_type_snp(void)
649  {
650  	return static_branch_unlikely(&isolation_type_snp);
651  }
652  
653  DEFINE_STATIC_KEY_FALSE(isolation_type_tdx);
654  /*
655   * hv_isolation_type_tdx - Check if the system runs in an Intel TDX based
656   * isolated VM.
657   */
hv_isolation_type_tdx(void)658  bool hv_isolation_type_tdx(void)
659  {
660  	return static_branch_unlikely(&isolation_type_tdx);
661  }
662